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Phosphate Losses on Four Grassland Plots Used for Dairy Farming

其他書名	Measured Phosphate Losses and Calibration of the Model ANIMO
出版	Alterra, Green World Research, 2000
URL	http://books.google.com.hk/books?id=l0YOtwAACAAJ&hl=&source=gbs_api

註釋Changes in phosphate concentrations and pools were measured at four experimental plots from 1997 to 1999. The plots received phosphorus surpluses of 0, 10 and 20 kg ha-1 a-1. Significant changes in the phosphate pools were not yet found. Phosphate concentrations, phosphate budgets and changes in phosphate pools were simulated with the nutrient model ANIMO in combination with the hydrological model SWAP. The model simulated the order of magnitude of the measured concentrations and Pw values quite well, although the temporary fluctuations in orthophosphorus and organic phosphorus did not always correspond to the measured values. Overall leaching fluxes were simulated quite well by the model, except for the peat soils where leaching fluxes were overestimated. Leaching fluxes of orthophosphorus were somewhat overestimated, whereas organic phosphorus fluxes were underestimated. The simulated phosphorus balance indicated that on average 0.9 to 3.6 kg ha-1 a-1 was lost by leaching and runoff. The largest losses were found in the sandy soils, which had the highest phosphorus contents in the lower part of the root zone.